GT500 alternators are prone to failure; high revs are the main culprit. These units were designed to spin at a maximum of 17 to 18000 RPM. Since the vast majority of us have modded these cars and raised the rev limiter beyond the factory setting we often see failures. Our BPS 10% underdrive pulley will keep the alternator revs within a more reasonable range while allowing sufficient charging in the lower RPM band. Save yourself an alternator and minimize the chances of failure with this 15 minute pulley swap!
This pulley is an inexpensive insurance for the rpm issues and is highly recommended on all 2007-2014 MODDED GT500s that spin the motor above the stock rev limiter setting (6250rpm)
25% underdrive pulley for those who spin their built motors above 7000 RPM. We have tested on our own shop car that with the 10% underdrive at 6800 RPMs the alternator does not charge anymore. Switching out to the 25% slows it enough to keep charging even at those higher RPMs.
Purchase of longer belt necessary